山竹岩黄芪青贮中优质乳酸菌的分离和鉴定

Isolation and Identification of High-Quality Lactic Acid Bacteria in Hedysarum fruticosum Pall.Silage

从山竹岩黄芪(Hedysarum fruticosum Pall.)青贮饲料中分离到3株乳酸菌(HF84,HF69,HF49)。经传统鉴定方法及16SrRNA序列分析,菌株HF84为蒙氏肠球菌(Enterococcus mundtii),菌株HF69为乳酸乳球菌乳酸亚种(Lactococcus lactis subsp.Lactis),菌株HF49为植物乳杆菌(Lactobacillus plantarum)。3株乳酸菌均为同型发酵乳酸菌,蒙氏肠球菌在pH 3.0条件下不能生长,乳酸乳球菌乳酸亚种在pH 3.0、温度5℃时及6.5%NaCl溶液中不能生长,植物乳杆菌均可在试验设定条件下生长。通过测定3株乳酸菌的生长曲线和产酸速率,菌株HF49生长速度快、产酸性能好,可作为制备乳酸菌青贮饲料添加剂的优良菌株。

Three strains of lactic acid bacteria were isolated from Hedysarum fruticosum Pall.silage.The 16S rRNA analysis and traditional identification methods indicated that three strains,Enterococcus mundtii（HF84）,Lactococcus lactis subsp.lactis（HF69） and Lactobacillus plantarum（HF49）,all were homofermentative lactic acid bacteria.HF84 could not grow at pH 3.0,HF69 could not grow under pH 3.0,5？校nd 6.5% NaCl conditions,while HF49 can grow well at all tested conditions.Through measuring the rate of lactic acid production and the growth curve,HF49 can be selected as excellent strain for preparing lactic acid bacteria additive due to its rapid lactic acid-production and growth speed.